If i’m off to play two hours of strenuous basketball, when is the best time to eat my Cliff Bar if i want to maximize it’s effect?
On a more general level, how does eating affect imminent exercise?
If I play ball at 7 p.m., does a big lunch with protein and carbos help?
What about carbo loading the night before a big race? Where is that energy stored after digestion? And how long before it goes away? Where does it go if it hasn’t been used?
Does any of this really matter? When i ran track in high school, they told us to avoid milk before a meet because it contained lactic acid–the substance that makes your muscles burn. I never understood the digestive connection to the muscular expression and regarded it as a myth. Of course, nutrition is important. But is there any proof that an energy bar really improves performance?
That’s a bunch of stupid questions for you. Maybe you can help me out with a couple…
From being in the low carb circle, I can give you the advice from this side:
Eat your bar long before you finish your activity. I usally have mine in the middle of a all day hike or ski, when I’m hungry. for a 2 h game, I’m not sure it’s needed.
1 & 2 As for carb-loading, I think it is not recomended even in low-fat circles any more - they say to have a slightly higher carb meal w/ protien and some fat. Your body quickly will convert any carbs to glycogen and fat - problem is that most peoples glycogen level is already full - leaving only one pathway. by mixing protien and fats you slow the rate of absorbtion of carbs. As a low carb-er, when I plan such a all day event, I will slightly increase my carb level the day before to maybe 60g- 80g to make sure that the glycogen levels are topped off.
3 - It should go away preaty quick, a big carb meal will raise your blood glucose level (BGL) very fast, your body counters this and lowers it as fast as it can to bring it into normal range and often overshoots causing your BGL to crash
4 - mainly to fat, as I mentioned your glycogen level is probally full already.
Also I don’t think there is any proof that energy bars improve preformance - they serve as emergency meal replacements.
For a ‘big game’ your body runs the first 4-8 minutes on glycogen then switches to fat burning anyway.
This is one of those questions where the answer depends on what you want to achieve what type of exercise you’re doing and what’s in your energy bar.
In simplified form when you eat food it gets digested and absorbed into the blood over a period of time, anything up to 24 hours. The time period depends on what you ate, how active you are, how much you ate and other factors. With something as simple as sugars the body absorbs them pretty fast, usually I can feel the sugar burst within 10 minutes. Stuff like starch, protein and fat take a lot longer. Once this stuff enters the bloodstream if it isn’t used it is stored initially as glycogen in the muscles and liver to get it out of circulation, then converted to fat.
Normally your body has a store of readily available energy in its muscles, but this is used up fairly rapidly. It then begins to mobilise the glycogen reserves in the muscles and other organs, and when this is gone it starts to burn fat to produce energy. Mobilising both glycogen and fat use energy. This is a bit of an oversimplified explanation but it should suffice.
If you eat a sugary meal just before exercise the sugar will be utilised by the muscled before or along with the glycogen, thus saving the body the effort of mobilising so much and theoretically giving better performance. Since starch is largely converted to sugars on digestion, a big carbohydrate meal some time before exercise will do the same. Carbo loading the night before exercise will have minimal benefit since most of the food will have been converted to fat by the time the race arrives. Your body has a big problem storing energy in any form other than fat. The theory behind carbo loading is that if you can time it just right (I assume 2-4 hours before the race but I don’t know) then your body will try to get the sugars out of circulation fast, and it does this by forcing the muscles to absorb it as glycogen. This extra glycogen is a much more efficient energy reserve than fat.
The problem with all this is that heavy exercise actually turns down the digestive process, meaning that a heavy meal sitting undigested in your gut at the beginning of heavy exercise will actually remain as a dead weight until after you finish. Added to this any fat in a meal during anaerobic activity, which basketball is unless you’re fairly fit, can cause problems when it enters the bloodstream as it cannot be cleanly burnt and can easily contribute to acid buildup. Proteins can produce similar problems, and can also lead to increased dehydration, they aren’t a good energy source and produce a lot of toxic wastes when burnt. On the upside increased amino acid levels in the blood from protein digestion during exercise will enhance muscle development.
All digestion also requires oxygen, which means that even if the gut is working it’s still taking oxygen away from your muscles where you want it. There’s a good reason why athletes usually only drink electrolyte drinks that contain nothing but sugar when exercising.
Assuming your energy bar is mostly sugar then it would probably do you good to eat it just before exercise (say 10 minutes to pluck a figure out of the air) since it’s not a big load to hold and sugar requires little energy to digest.
But to further confuse things the body can’t keep sugars in the bloodstream, and after you eat will take steps to pull them into the muscles/liver. If this starts it can produce lower energy levels and that drowsy feeling you get after a big meal, and this can lower performance, so try not to starve yourself before exercise and stay warm after eating so the sugars cant buildup in your bloodstream. This can also apply if you’re on the bench for any period of time.
As for the lactic acid in milk thing, if I remember my physiology right only rotten milk and yoghurt should contain lactic acid. Milk contains lactose, a sugar that provides very good energy. Of course if you’re from a non-European background it may cause problems simply because you can’t digest it. Lactic acid is a product of anaerobic respiration and shouldn’t be readily affected by lactose levels in the blood.